Sunn Hemp cover crop legume seed is a warm season legume, upright and quick in its growth habit. Sunn Hemp needs 60°F soil temps before it can planted and will kill at the first signs of frost. Higher seeding rates of Sunn hemp will help with weed suppression.

• Produces significant amounts of nitrogen in 60 days depending on conditions
• Tolerant of dry conditions and low fertility
• Can add up to 5,000+ lbs. of biomass per acre in 7-8 weeks
• Research has shown levels of nematode suppression (root knot, borrowing)

Visit our Mixes page to explore premium Soil First mixes blended with different legume varieties. View mixes.

Non-Forage Benefits:
1 = Poor; 5 = Excellent

Compaction Alleviation: 2
Weed Suppression: 4
Biomass Production: 5
Erosion Control: 3
Disease/Pest Control: 3
Pollinator/Beneficials: 4
P & K Cycling: 3
Ease of Establishment: 3

Nitrogen Fixer/Scavenger: Fixer

Nutritional Value:
Values Vary Greatly Depending on Maturity

Crude Protein: 25
NEL¹ Mcal/lb.: Varies Greatly
ADF%²: Varies Greatly
NDF%³: Varies Greatly
TDN: Varies Greatly
DM Tons/Acre: 1-5
Days to First Harvest: 40-45
Days to Next Harvest: –

¹- Net Energy for Lactation = Energy available after subtracting digestive and metabolic losses
²- Acid Detergent Fiber = Low values mean more digestible
³- Neutral Detergent Fiber = Low values mean cows can eat more

Ranking (Good, Better, Best):
Graze: Better
Baleage: Good
Chop: Best


Planting Time:

Seeding Rate:
Mono (lbs./acre): 15
Mix (lbs./acre): 5-8
Forage (lbs./acre): 5-15

Seeding Info:
Carbon/Nitrogen Ratio (C:N): 18:1-29:1
Seeding Depth (in./with drill): 1/2-1
Seeds/lb.: 15,000
Bulk Density (lbs./ft.): –
Aerial Application Rate: NR
Germination Soil Temp.: 65 F
USDA Hardiness Zone: Frost
Days to Emergence: 3-7


  • Prefers soil pH levels above 6 (6–7)
  • Kills at first frost, or control by mowing or herbicide at first flower for maximum benefit
  • Residue (green manure) should be incorporated while still green
  • In far southern areas (below 28° latitude), sunn hemp will produce seed which can be toxic to livestock

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